Strong NE winds will transport snow away from previously wind-loaded N-NE-E aspects and create new wind slabs on the S-SW-W aspects and cross-loaded NW and SE aspects. These new wind slabs may be sensitive to human-triggering today and human-triggeredwind slabavalanches will be possible. In addition to these newly formed wind slabs, some of yesterday's wind slabs may still linger on wind-loaded N-NE-E aspects and cross-loaded NW and SE aspects in areas that have not been scoured by the NE winds. In either case, these wind slabs exist on top of smooth icy surfaces and weak old snow. While many of these wind slabs should remain small and not extend very far away from ridgelines, some larger and deeper wind slabs could exist in the most heavily wind loaded areas or in areas that received the most new snow. Avalanches resulting from these wind slabs could involve enough snow to bury a person. The wind slabs should be denser and harder than yesterday's wind slabs. They could break above the person who triggers them or not fail until that person has already committed to the slope.

Use clues like blowing snow, hollow sounding snow, cornices above slopes, drifted snow, and other wind created textures to identify where wind slabs may exist and avoid traveling on or under steep slopes in those areas in favor of less exposed, less steep, more sheltered slopes where softer snow may reside.

Avalanche Problem 2: Loose Dry

Type
?

Aspect/Elevation
?

Likelihood
?

Certain

Very Likely

Likely

Possible

Unlikely

Size
?

Historic

Very Large

Large

Small

A cold clear night should have caused yesterday's snow to weaken and become less cohesive in areas sheltered from the winds. While weaker surface snow means slabavalanches should be unlikely in sheltered near and below treeline areas, loose dry sluffs could occur today. Steep slopes where the new snow rests on top of smooth icy old snow surfaces or on top of loose weak old snow represent the most likely terrain to trigger a loose dry avalanche. These sluffs could involve enough snow to knock a person off balance but may not involve enough snow to bury a person. With the current early season conditions, getting knocked off balance could result in getting pushed into a rock, tree, stump or other hard immovable objects. These sluffs would could also have more serious consequences in areas near cliffs or other terrain traps.

* Snow totals averaged about 4 inches across the forecast area yesterday.

* Weak snow still exists under the new snow in sheltered areas, but the new snow did not have enough slab characteristics to form a storm slab problem.

* The most snow coverage still exists in areas north of Emerald Bay above 8,000'. Below 8,000' snow coverage remains patchy and shallow. South of Emerald Bay, less snow exists with areas below 8,500' holding very little snow.

Weather and CURRENT CONDITIONS

weather summary

After a short burst of snowfall that totaled about 4 inches in most places yesterday morning, the cold front departed the area leaving cold dry weather behind. The wind shifted to the NE yesterday evening and has been steadily increasing since then. The Ward Peak sensor along the Sierra Crest registered sustained NE winds in the 50 to 70 mph range with gusts as high as 92 mph this morning. These NE winds should peak by midday and then start to decrease this afternoon. By tomorrow the forecast calls for light winds and warming temperatures at the upper elevations. Some thin high clouds may also develop over the area tonight and tomorrow.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS

For 7000 ft. to 8000 ft.

Thursday

Thursday Night

Friday

Weather:

Sunny

Increasing high clouds

Thickening high clouds

Temperatures:

31 to 35 deg. F.

15 to 21 deg. F.

40 to 45 deg. F.

Mid Slope Winds:

Northeast

Variable

Southwest

Wind Speed:

10 to 20 mph

Light

Light increasing to 10 mph

Expected snowfall:

0

0

0

For 8000 ft. to 9000 ft.

Thursday

Thursday Night

Friday

Weather:

Sunny

Increasing high clouds

High clouds thickening

Temperatures:

28 to 33 deg. F.

26 to 31 deg. F.

35 to 40 deg. F.

Ridge Top Winds:

Northeast

Northeast shifting to northwest after midnight

West

Wind Speed:

25 to 45 mph with gusts to 75 mph

15 to 25 mph with gusts to 55 mph decreasing to 10 to 20 mph after midnight

15 to 25 mph with gusts to 45 mph

Expected snowfall:

0

0

0

Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258

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This website is owned and maintained by the non-profit arm of the Sierra Avalanche Center. Some of the content is updated by the USDA avalanche forecasters including the forecasts and some observational data. The USDA is not responsible for any advertising, fund-raising events/information, or sponsorship information, or other content not related to the forecasts and the data pertaining to the forecasts.